Robotic vehicles are often used to navigate or traverse varying terrain. As is well known, wheeled robotic vehicles, both large and small, are particularly well adapted for travel over relatively smooth terrain, such as roads and smooth floors. However, it is often necessary for robots to traverse terrain that is not smooth, such as stairs or curbs. Moreover, it is often necessary for robots to traverse terrain that may pose a danger to humans, such as those situations presenting an environmental risk, military risk, or the like. Often robotic devices are useless in these dangerous situations because of their inability to successfully and reliably traverse any severely broken and/or fractured ground that they may encounter. Attempts have been made to overcome the numerous disadvantages of wheeled robotic vehicles in these situations by simply increasing the diameter of the wheels or adding tank crawler tracks to increase the ability of the robotic device to traverse large objects or spans. However, these solutions include additional disadvantages, such as increasing the overall size of the vehicle, which may inhibit the robot's ability to pass through small openings.
Furthermore, many robots suffer from being rendered immobile as a result of a rollover or other situation that prevents contact of their propulsion member(s) on the ground surface. That is, should a wheeled robot encounter a grade sufficient to roll it on its side, the wheels are no longer capable of propelling the robot. In terrains that pose a risk to humans, such rollovers may render the robot unrecoverable.
Recently, articulating robotic mechanisms, which are also sometimes referred to as snake or serpentine robots, have been developed that successfully overcome the disadvantages of the prior art and navigate such inhospitable environments. Such robots typically employ three or more rigid segments, which are connected through joints. The joints may permit one, two, or more Degrees-of-Freedom (DOF). Examples of commonly invented robotic mechanisms can be found in U.S. Pat. No. 6,512,345 and U.S. patent application Ser. No. 10/318,452, the disclosures of which are incorporated herein by reference. However, often times prior art robotic devices fail to provide adequate range of motion and/or force necessary to articulate the various robotic segments in demanding environmental situations
Accordingly, there exists a need in the relevant art to provide a joint actuator that is capable of providing improved range of motion and/or articulating force. Further, there exists a need in the relevant art to provide an apparatus for traversing obstacles that overcomes the disadvantages of the prior art.